Change gitlab-ci.yml to try and get environments working

.gitlab-ci.yml

@@ -6,6 +6,12 @@ build:
   script:
     - docker build . -t "cmc:latest"
 
-deploy:
+deploy_staging:
+  stage: deploy
   script:
-    - echo hello world
+    - echo "Deploy to staging server"
+  environment:
+    name: staging
+    
+  only:
+  - master